If I'm true, JP or Bruno wrote that the caps in the UcD do not need to be replaced with low ESR values as the circuit was designed to use standard ESR caps.
classd4sure said:
Ok, I see, also not that much power and no regulation, my SMPS is pretty huge but can deliver lots of power and nicely regulated so I stick with that one.
Best regards
Gertjan
Bgt said:
Yes, the Panasonic FC should be quite good. However, I think the current UcDs have the BC 136 series cap, correct? That one is spec`ed very well. At digikey, you can order the BC cap only large quantities. The Panasonic FC is more expensive but can be ordered in lower quantities. If you use the 100V caps, loss is again a little bit lower.
Best regards
Gertjan
ghemink said:
Yeah, but I guess they save a little weight/space/cost(?), and maybe more hum immunity if you're prone to really bad layouts ?
It's good to know else is out there anyway, wouldn't want to miss out would we?
Regards,
Chris
I believe he was reffering to one particular cap to avoid ringing, the filter cap in LC perhaps? The other caps better be low ESR.
I did a quick search but did not find the post.
Anyway, there is some confusion about this topic (at least for me).
Could some charitative soul draw a simple diagram to show PCB position, number and nickname of each tweakable cap?
That will be very useful to understand each post, IMHO.
Thanks
Mauricio
i "borrowed" Julien_M's pic for my own site (hope you don't mind, if you do please let me know) and i edited it somewhat:
An externally hosted image should be here but it was not working when we last tested it.
Thanks, Matjans 😀
So, which is the cap that is better to maintain as mid ESR? Is it bootstrap?
For a start I guess I will:
1) remove "input caps" and solder directly the input wires (OCC cooper) to the (-) cap hole.
2) swap "PSU caps" for Panasonic FC 470 or 680uF/100V.
3) Change "low voltage decoupling caps" to BG N, single or superE-cap configuration.
4) change "output filter cap" if everyone says it's not dangerous.
To mantain the nomenclature.
Best regards
Mauricio
So, which is the cap that is better to maintain as mid ESR? Is it bootstrap?
For a start I guess I will:
1) remove "input caps" and solder directly the input wires (OCC cooper) to the (-) cap hole.
2) swap "PSU caps" for Panasonic FC 470 or 680uF/100V.
3) Change "low voltage decoupling caps" to BG N, single or superE-cap configuration.
4) change "output filter cap" if everyone says it's not dangerous.
To mantain the nomenclature.
Best regards
Mauricio
maxlorenz said:
Hi,
1. Depends which version you have, if you plan on doing that, make sure you have the version that has the coupling caps before the op amps and not after it. Otherwise you'll be bypassing the input stage.
The low voltage caps aren't for decoupling at all.
matjans said:
Matt,
I assume this is the UcD400 module? If this is the case what you have identified as the bootstrap cap is actually one of the output device filters and the bootstrap is the next one out. Thought I had better point this out so someone doesn't replace it with a lower voltage cap. It should also be pointed out that these 2 blue caps next to the output devices act as snubbers and shouldn't be replaced.
Roger
The Panasonic FM Series are worth trying also. Panasonic claims they are a lower impedance higher ripple current version of the FC. Lifetime is rated at 2000-7000 hours and the ones I bought fit perfectly. Available at Digikey.
The fly in the ointment is that they are only available with 50V ratings and below. At least you can use them on the UCD180s for the power supply caps and as low voltage decouplers.
The fly in the ointment is that they are only available with 50V ratings and below. At least you can use them on the UCD180s for the power supply caps and as low voltage decouplers.
Kevin Haskins said:
You really can't use them at all, unless for some reason you want to limite your rails to say 40Vdc worst case.
Otherwise you cut the capacitor voltage tolerance down by 10% from 20% for the recommended voltage rating of the module (45Vdc), and for its absolute max rating (50Vdc), the data sheet would then say "Absolute maximum ratings indicate limits at which damage will occur."
Instead of "Absolute maximum ratings indicate limits beyond which damage may occur."
Are you still comfortable giving that cap as a recommendation, and have you tried them yourself?
I'm also a little disturbed by so many mentions of these "low voltage decoupling caps", has anyone actually seen one?
Guys if you don't know what you're messing with...
I am more confused now!
Our denomination was short-lived.
Dear Stef1777, it's a pair of non-polar BG's in "antiparallel" mode. I've tried N caps as coupling caps with success and 0.1uF NX-HiQ with variable success as PS decoupling due to ringing (but that is probably because I'm a nulity at making PS'). When I manage to make them work they are, IMHO, transparent
Take a look:
http://www.blackgate.jp/english.htm
http://www.acoustic-dimension.com/blackgate/techEcap.htm
Ah! I forgot: very long burning-in time. Five to 14 days 😱
Before they do they can sound totally awful: don't discourage. You'll regret it.
Of topic: I've got my Sikorel's playing 😉
Also interesting are Rubicon's ZL (better bass and more round-sounding than FC's) but, do they come in more than 50V?
They are before, thanks for your interest.
So, can we start again and put some order to understand each one's posts?
Gratefully yours...
Mauricio
On the modules there is a sticker with the serial number. Also on this sticker is a version number.
It would be nice to have a sticky here with the changes in the versions.
Apparently I have a version with input caps behind the opamp (which seems an odd thing to do?)
Can I replace them? What if I short them and add caps on the input pins? Can I do that or is the rest of the circuitry different as well?
It would be nice to have a sticky here with the changes in the versions.
Apparently I have a version with input caps behind the opamp (which seems an odd thing to do?)
Can I replace them? What if I short them and add caps on the input pins? Can I do that or is the rest of the circuitry different as well?
Yves Smolders said:
Hm,
I think this thread has gotten to a point where nobody is reading anymore but just keep posting.
I'm pretty sure Bruno and Jan-Peter already answered all those questions and alot of the recent ones asked earlier on in this very thread.
On a side note, super E sounds very interesting.
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